As spring approaches and warmer weather beckons, Rick Lovett looks at the science of training for hot-weather performance, and also explains why and how heat training can benefit your performance ALL year round MORE
Short and sweet – why all sportsmen and women should consider 40m sprinting
The relevance and potential benefits of 40m sprinting
Many team sports athletes will go through a battery of fitness tests throughout their career. One of the most widely used is the 40m sprint (the 40-yard dash in the USA), which is used to test speed. James Marshall explains how you can benefit from 40m sprint training
While it’s true that there are other speed tests that are relatively easy to administer and which provide immediate feedback to coaches and athletes, the 40m test is so prevalent in sporting circles that athletes may benefit from training plans that improve their 40m sprinting, as well as their linear speed, to assist their sporting performance. Indeed, in the USA, whole training programmes, websites and camps are devoted to ‘improving your 40’.
This data is relevant to sports such as field hockey, football and rugby, where players are not only required to run bursts of similar distances during the game, but also need to have high top speeds and good acceleration, eg being first to a ball or racing back to get into defensive position; 40m sprinting can also be relevant in sports such as ice hockey (which has no running in it) as a measure of power and leg speed(1). One study showed a high correlation between ice hockey players’ 40yd times and their shooting performance within matches(2).
Running, jumping or squatting?
In order to improve running speed over 40m shouldn’t you just practise running 40m? Inevitably, practising any skill that is going to be tested will result in improvements in untrained subjects as a learning effect takes place. However, developing strength through weight training exercises such as the squat, or power through exercises such as plyometrics or jump squats has also been advocated as an alternative to just running.
As usual, research is not 100% clear on the answer, mainly due to the design of the studies and the use of ‘recreationally trained’ or ‘untrained’ subjects (such as university students) who are usually male, instead of well trained athletes. The training effect demonstrated in these studies may therefore not be especially relevant for those who are better trained or are female.
Decreasing the ground contact time without enhancing the ability to increase force proportionately will result in slower linear speed because the acceleration produced will be less. Developing power withresistance training is usually achieved by either using heavy weights (70-90% 1RM) and low velocity or lighter weights (30-50% 1RM) and high-velocity movements. Both have been found to be effective when using squat, hip extension and hip flexion movements in improving 20m acceleration time(4).
Improving maximal leg strength may prove to be crucial in improving speed in untrained subjects, but less so in experienced athletes. This is due to the fact that a large increase is needed in leg strength before a corresponding increase in speed is seen. A large strength increase is easier to achieve in untrained subjects than those who have been training for 10 or more years.
In trained subjects, squatting immediately before sprinting may produce an acute effect over 40m due to postactivation potentiation (PAP)(5). One set of three heavy squats at 90% 1RM were effective in reducing 40m sprint time in college American football players compared with three squat jumps with a 30% 1RM load. A four-minute rest period was enforced between the exercise and the sprint. However, this is not recommended for untrained subjects as the squats would have an unduly fatiguing effect and reduce the ability to produce power.
The recovery phase
Most studies have looked at training the drive phase of the sprint action; however, training the recovery phase could be just as important. One study using untrained subjects improved 40yd times over eight weeks by using elastic bands to improve hip flexor strength for the recovery phase(6). The subjects tied the elastic band around their ankles and then reproduced the high knee lift against the resistance of the band. The subjects improved hip flexor strength by 12% and decreased their 40yd time by 9%.
The idea of reproducing this action under load is sound, but it is unlikely to work in trained subjects due to the limitations of using elastic bands. Unlike using free weights or cables, which require a large initial force to overcome inertia, bands have little inertia at the beginning of the movement, but resistance increases towards the end of range. This results in early deceleration, which is counterproductive in most athletic movements.
Sprint training protocols
As the 40m is a very specific running test, and most training time is limited, the running drills need to be very effective. Running a series of 40m sprints, with ‘walk back recovery,’ which is common in team environments, may not produce the best results. Instead, carefully managed rest times that allow recovery of the phosphocreatine energy system should be used. This will then help the athlete run at their top speed for each sprint in the training session. Rather than run the same set of drills in each session, it may be best to include some over-speed and uphill sessions as well as normal sessions.
Incline or running with resistance is designed to increase ground contact time and reduce stride length, which may be useful in the initial 15m of acceleration. Downhill running or overspeed training is designed to increase stride length and reduce ground contact time, important in the 15-40m phase of the sprint. When using inclines, declines, resisted or overspeed training methods, it is important to observe running mechanics. Too much incline or resistance will result in severely altered running styles and poor posture, which then has a detrimental effect when the resistance is removed. The same is true for decline or overspeed training (being towed).
Two recent studies had different views on this. The first used a protocol of towing (over-speed sprints), pushing (resisted sprints) and normal sprints and compared the three groups over 22m(7). The subjects were untrained college students and the sprint sessions were conducted three times a week for six weeks and consisted of sprinting 22m five times.
All three groups improved their times at their own protocol (ie the resisted group got better at running against resistance) but the transference to flat speed was greatest in the normal sprint group and then by the overspeed group. The short-term nature of this study indicates that the adaptations to the training were neuromuscular in nature; the subjects became more efficient at their drills. This may not have transference to sport specificity, but if you are trying to get good at a one-off 40m test, then training at that speed for six weeks may help. However, in the longer term, you are unlikely to get better results by just doing that.
The second study combined uphill, flat and downhill running into the same session to provide resisted, tempo and overspeed stimulation to the subjects and compared that to just uphill, flat or downhill sessions (without resistance or towing)(8).
The researchers designed and built a wooden platform that had a 20m flat portion, a 20m incline at 3 degrees, a 10m flat portion at the top, a 20m decline at 3 degrees and then a flat 10m at the end. The combined uphill/downhill group ran this 80m total six times with 10 minutes’ rest between sprints, three times a week for six weeks. The other groups ran the same total distance, but in shorter bursts using the same platform, so they ran 12 sets of 40m combining the flat and either the down or the up portion of the platform.
At the end of the six weeks training, the subjects were tested over 35m and the combined uphill/ downhill group showed a 3.4% increase in top speed with the downhill group showing a smaller 1.1% increase. The flat and uphill training groups made no significant changes to running speed after six weeks of training.
The key factor distinguishing between the downhill only group and the combined uphill/downhill group is that the latter had their neuromuscular system overloaded, then unloaded and then assisted. This loading and unloading in the same session could be the difference and is worth trying in training.
Other benefits of practising ‘the 40’
Regular sprint training can lead to better sprint times, but could it also be used as a training tool in itself leading to other physiological improvements. Plyometrics are often used as an effective training method to help reduce ground contact time for sprinters and jumpers. A Croatian study compared a sprint training protocol with a plyometric protocol over 10 weeks and looked at the effects on drop jumps, countermovement jumps, squat jumps and squat strength as well as 20m sprint time and 20yd shuttle runs(9).
Both groups improved their jumps but the sprint group also improved their isometric squat strength and their speed and agility scores. This study showed that sprinting could be used as a training tool that has similar or better effects than plyometrics. The same researchers also analysed anthropometric characteristics of the two groups and found that the only significant change was a 6.1% reduction in body fat in the sprint group(10).
Assumptions may be have to be made in designing training protocols for well trained athletes due to the paucity of research using trained subjects. However, it does appear that once a well developed strength base is in place with sound sprint mechanics, the use of different sprint speeds and drills followed by normal mechanics at top speed is more effective than running just flat speed drills.
In untrained subjects the most effective way to improve 40m speed over the short term (circa six weeks) is to practise the test and coach the running style well. This will be effective once, but for those athletes who are tested regularly, a solid strength base needs to be developed in combination with power exercises either in the gym or using plyometrics.
It’s worth commenting on the use of time spent on sprint drills. Most coaches who have limited access to their players will not allow players to spend even 10 minutes doing nothing in their training session; taking up a whole evening doing six maximal sprints over 40m with 10 minutes’ recovery will not therefore go down well. Try doing that on a rainy night in January and your players won’t like it much either! Doing 20 sets of 40m sprints with ‘walk back recovery’ may look busier and the players will be tired, but it won’t help their 40m speed either!
Working on lower body strength and power in the gym, however, will have the two-fold effect of improving both sprint speed and overall conditioning, which will help in contact and collision sports.
James Marshall MSc, CSCS, ACSM/HFI, runs Excelsior, a sports training company
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